1. Field of the Invention
The present invention relates to a semiconductor package, and, more specifically, to a stacked semiconductor package having a plurality of input/output members.
2. Description of the Related Art
In typical semiconductor packages, a substrate is electrically connected to a semiconductor die mounted thereon. The substrate is then electrically and mechanically connected to an external device so as to ensure a stable electrical connection between the semiconductor die and the external device.
The substrate can be either a lead frame or a laminate circuit board. A semiconductor package using a lead frame is generally manufactured by bonding a semiconductor die onto a die paddle. The semiconductor die is coupled to a plurality of leads using conductive wires. The semiconductor die and the leads are encapsulated with an encapsulant, allowing part of the leads to be exposed from lateral sides of the encapsulant. The exposed leads are connected to an external device. On the other hand, a semiconductor package using a laminate circuit board is manufactured by bonding a semiconductor die onto a circuit board. The semiconductor die is coupled to the circuit board using conductive wires. The semiconductor die and the circuit board are encapsulated with an encapsulant and an array of solder balls are fused to one side of the circuit board. The solder balls being connected to the external device.
In conventional semiconductor packages using a lead frame, only the leads extending from lateral sides of the encapsulant, for example, in second and fourth directions of the encapsulant, are used as input/output members. Thus, the conventional semiconductor packages do not meet the demand for an increased number of input/output members. As an attempt to increase the number of the input/output members, it has been suggested to narrow the pitch of the leads or manufacture the semiconductor packages in a larger size. However, there is a technical limitation in narrowing the lead pitch during manufacture of a lead frame. Also, large-size semiconductor packages go against the current trend toward smaller and lighter packages.
In semiconductor packages using a laminate circuit board, solder balls arrayed on one side of a circuit board are used as input/output members. The semiconductor packages using a circuit board are smaller in size and have a larger number of input/output members than the packages using a lead frame.
However, conventional semiconductor packages in either type have a limitation on the number of input/output members because they use only one type of input/output members. In other words, leads are only used as input/output members in a semiconductor package using a lead frame, whereas solder balls are only used as input/output members in a semiconductor package using a circuit board. New type semiconductor packages using both leads and solder balls to increase the number of input/output members have not yet been available.
Also, conventional semiconductor packages have a low heat release efficiency because they only use either the leads or the solder balls as heat release paths. Due to a high degree of integration and complicated functions, recently available semiconductor packages generate more heat during operation than pre-existing ones. However, the packages cannot effectively release the generated heat with the limited number of heat release paths.
Therefore a need existed to provide a semiconductor package and a method of producing a semiconductor package that overcomes the above problems.